BIO 253 LATEST 2026 EXAM QUESTIONS AND SOLUTIONS
RATED A+
✔✔What makes up a phospholipid bilayer - ✔✔A phosphate head which is hydrophilic
(inside and outside of cell)
A phosphate tail (fatty acid tail) which is hydrophobic
✔✔Proteins (amino acids) - ✔✔Made in rough er
Building blocks of proteins
✔✔Rough endoplasmic reticulum - ✔✔transport and storage
✔✔What happens if an amino acid chain is too long - ✔✔They start to fold over
✔✔What is a peptide bond - ✔✔bond between amino acids
✔✔Nucleic acids - ✔✔RNA and DNA
ATP
✔✔Does more or less hydrogen cause something to be acidic - ✔✔More
✔✔Does more or less hydrogen them make something alkaline - ✔✔Less
✔✔What is neutral pH - ✔✔7
✔✔Log scale pH goes up or down by what number - ✔✔10
✔✔Can proteins be renewed - ✔✔No they need to start from scratch
✔✔What is homeostasis - ✔✔Maintaining a stable internal environment
✔✔What is negative feedback - ✔✔Maintaining homeostasis
✔✔Example of positive feedback - ✔✔Childbirth
Blood clotting
Sneezing
✔✔DNA what goes with what - ✔✔A and t
C and g
✔✔What goes with white fur RNA - ✔✔A and u
, C and g
✔✔What is a codon? - ✔✔a sequence of three nucleotides that together form a unit of
genetic code in a DNA or RNA molecule.
✔✔What is the anticodon? - ✔✔a sequence of three nucleotides forming a unit of
genetic code in a transfer RNA molecule, corresponding to a complementary codon in
messenger RNA.
✔✔What is the stratum corneum? - ✔✔outermost layer of epidermis
Dead skin cells found
✔✔Stratum basale - ✔✔the deepest layer of the epidermis
Cell activity
✔✔Building blocks of carbohydrates - ✔✔monosaccharides
✔✔What do triglycerides do - ✔✔Store fat
✔✔Gluconeogenesis - ✔✔Production of glucose which is the last resort from fat and
muscle
✔✔Building blocks for DNA and RNA - ✔✔Nucleotides
✔✔Rule for inorganic compounds - ✔✔Small
Can have one hydrogen or one carbon but not both
✔✔Roll for organic molecules - ✔✔Needs to be big
Have both carbon and hydrogen
✔✔What do proteins end with - ✔✔Ase
✔✔What is anaerobic - ✔✔Does not require oxygen
✔✔What does aerobic require - ✔✔Oxygen
✔✔What is a solvent - ✔✔the substance in which the solute dissolves
✔✔What is a solute - ✔✔The substance that is dissolved
✔✔What muscle is the diaphragm - ✔✔Skeletal muscle
✔✔What muscle examples of smooth muscle - ✔✔Aorta
RATED A+
✔✔What makes up a phospholipid bilayer - ✔✔A phosphate head which is hydrophilic
(inside and outside of cell)
A phosphate tail (fatty acid tail) which is hydrophobic
✔✔Proteins (amino acids) - ✔✔Made in rough er
Building blocks of proteins
✔✔Rough endoplasmic reticulum - ✔✔transport and storage
✔✔What happens if an amino acid chain is too long - ✔✔They start to fold over
✔✔What is a peptide bond - ✔✔bond between amino acids
✔✔Nucleic acids - ✔✔RNA and DNA
ATP
✔✔Does more or less hydrogen cause something to be acidic - ✔✔More
✔✔Does more or less hydrogen them make something alkaline - ✔✔Less
✔✔What is neutral pH - ✔✔7
✔✔Log scale pH goes up or down by what number - ✔✔10
✔✔Can proteins be renewed - ✔✔No they need to start from scratch
✔✔What is homeostasis - ✔✔Maintaining a stable internal environment
✔✔What is negative feedback - ✔✔Maintaining homeostasis
✔✔Example of positive feedback - ✔✔Childbirth
Blood clotting
Sneezing
✔✔DNA what goes with what - ✔✔A and t
C and g
✔✔What goes with white fur RNA - ✔✔A and u
, C and g
✔✔What is a codon? - ✔✔a sequence of three nucleotides that together form a unit of
genetic code in a DNA or RNA molecule.
✔✔What is the anticodon? - ✔✔a sequence of three nucleotides forming a unit of
genetic code in a transfer RNA molecule, corresponding to a complementary codon in
messenger RNA.
✔✔What is the stratum corneum? - ✔✔outermost layer of epidermis
Dead skin cells found
✔✔Stratum basale - ✔✔the deepest layer of the epidermis
Cell activity
✔✔Building blocks of carbohydrates - ✔✔monosaccharides
✔✔What do triglycerides do - ✔✔Store fat
✔✔Gluconeogenesis - ✔✔Production of glucose which is the last resort from fat and
muscle
✔✔Building blocks for DNA and RNA - ✔✔Nucleotides
✔✔Rule for inorganic compounds - ✔✔Small
Can have one hydrogen or one carbon but not both
✔✔Roll for organic molecules - ✔✔Needs to be big
Have both carbon and hydrogen
✔✔What do proteins end with - ✔✔Ase
✔✔What is anaerobic - ✔✔Does not require oxygen
✔✔What does aerobic require - ✔✔Oxygen
✔✔What is a solvent - ✔✔the substance in which the solute dissolves
✔✔What is a solute - ✔✔The substance that is dissolved
✔✔What muscle is the diaphragm - ✔✔Skeletal muscle
✔✔What muscle examples of smooth muscle - ✔✔Aorta
